Absence of the Hanle effect in organic semiconductors (OSCs)
Comprehensive Exam
3:00 pm
Jorgensen Hall Room: 207
Speaker: Kishan Sinha
Advisor: Xiaoshan Xu
Abstract:
The Hanle effect is the most direct and unequivocal proof of presence of non-equilibrium spin populations in a non-magnetic (NM) medium. This effect has been used to demonstrate injection and diffusion of spin-polarized electrons in inorganic NM materials. In case of OSCs, however, this effect has not been observed even though the injection of spin-polarized carriers has been confirmed by other methods. I will address the absence of Hanle effect in OSCs by highlighting the contrast in mechanisms that govern carrier transport in organic and inorganic NM materials. I will also introduce an exchange-mediated spin transport formalism for organic semiconductors proposed by Z. G. Yu that attempts to address the absence of the Hanle effect in OSCs.
Reference: Z. G. Yu, PRL 111, 016601 (2013)
Advisor: Xiaoshan Xu
Abstract:
The Hanle effect is the most direct and unequivocal proof of presence of non-equilibrium spin populations in a non-magnetic (NM) medium. This effect has been used to demonstrate injection and diffusion of spin-polarized electrons in inorganic NM materials. In case of OSCs, however, this effect has not been observed even though the injection of spin-polarized carriers has been confirmed by other methods. I will address the absence of Hanle effect in OSCs by highlighting the contrast in mechanisms that govern carrier transport in organic and inorganic NM materials. I will also introduce an exchange-mediated spin transport formalism for organic semiconductors proposed by Z. G. Yu that attempts to address the absence of the Hanle effect in OSCs.
Reference: Z. G. Yu, PRL 111, 016601 (2013)